Distribution of Chlorinated Hydrocarbon Pesticides and PCBs in the ...

observed in the Play 1986 20 um and 73 um mesh samples.
Nauplii and early copepodite stages comprised a higher
percentage of individuals in the August 1986 collection as
would be expected if adults produced eggs during July and
August.
The broad seasonal pattern of changes in zooplankton
abundance and biomass were that large bodied copepods
dominated samples collected in May and June (>50% of the
numbers of individuals and biomass). In August there was a
shift to smaller sized species (mostly < %m) such as Oithona
similis, Oncaea borealis, Microcalanus sp. and unidentified
copepod nauplii and copepodites. The abundance of
phytoplankton in the August 1986 samples made seperation and
identification of small copepods difficult.
b) Benthic Fauna
The most abundant amphipod species attracted to bait was
Tmetonyx cicada. ~ndividuals were 3 - 5 cm total body
length. They were obtained alive and it was possible to hold
individuals at - 1. OoC in seawater in a container surrounded
by snow, Bait was protected in Nitex mesh holders to prevent
ingestion to avoid contamination of tissue samples to be used
for organochlorine analyses. However, amphipods held for
several days egested very little material. It was assumed
that animals separated for analyses had empty guts.
Subsequent microscopic examination preserved individuals
showed that amphorous material partially filled the guts of
"%i
more than 50% of the amphipods (n=35).
Andaniexis m was the second most abundant lysianassid
species collected with almost equivalent numbers of Anonyx
nusax (maximum length 3.5 em). Other smaller species
(Orchomene m. and Menisrates m.; 1-2 mm length) were
present but abundance was low in all samples.
Other non-crustacean benthic species attracted to bait
included unidentified brittle stars, shrimp, gasteropod